Process of producing aluminum alloy rivets



Patented Dec. 1, 1936,

UNITED STATES PATENT OFFICE PROCESS OF PRODUCING ALUMINUM ALLOY BIVETS Sven E. Hyhinette and Justin E. Tingay, Jackson, Mich, assignors to The Nicralumin Company,- Jackson, Mich, a corporation of Michigan No Drawing. Application February 23, 1934,

Serial N0. 712,484

14 Claims. (or. 148-115) containing considerable quantities of copper and silicon, and are, therefore, subject to spontaneous aging. As a consequence, such rivets are made from annealed or cold worked wire and the consumers have to quench the rivets within one hour before using them. An improvement has recently been made in this practice whereby the quenched rivets are held at a low temperature,

so as to retard the spontaneous aging. However, all practices, up to the present development, have necessitated the requenching of the rivets from time to time so as to make sure that heading up of the rivet is made before any considerable age hardening has taken place. Obviously,

any procedure which is so dependent upon the time element between quenching and heading of the rivet is .uncertain and unreliable and it is a well known fact that airplane, zeppelin, bus and truck structures have heretofore sufiered.

from so-called "popping of rivets, or in other words, the heads of the aluminum alloy rivets fall off. This failure of riveted structure is mainly attributable to age hardening before heading up of the rivet. Under present practice, satisfactory fabrication rests entirely upon the workman's judgment as to the lapse of excessive time between the quenching and the riveting operation rendering the rivets unfit for use without requenching. In all events, the original head of the rivet is much softer than the finally headed up end of the rivet.

Generally, it becomes the object of the present invention to provide aluminum alloy rivets which obviate the above objections and disadvantages and to produce rivets which are equally strong in both ends, which are more reliable and even in quality and which are not subject to the workmans opinion of whether they are too hard or not, at the time of the riveting operation, to-

aged aluminum alloy rivet of such'stable characteristics as to permit the'use of the same, with substantially uniform results, an indefinite period afterheat treatment. Another object is to provide aluminum alloy rivetscharacterized by having both heads thereof of approximately the same hardness. A further object is to do away with the necessity of having a heat treating operation in every riveting shop. These and other objects of the invention'will be more fully set forth in the description to follow.

In carrying out the invention, alloys which age spontaneously cannot be used. For this reason the copper content must be held within a definite range. Furthermore, high silicon alloys are not desirable because of the excessive hardness imparted by the heading up of the althe metal is such as not to be subject tomore than asvery slight aging at ordinary temperatures. v

By way ofan example, an alloy containing approximately .5% to 1% nickel, .1% to 1% copper, 25% to .5% chrome group metals and/or manganese with about magnesium has been found' to be satisfactory. No silicon and iron is added in the alloy except'such quantities as enter into the alloy as so-called impurities. That is to say, there may be present about /2% each of iron and silicon. It is to be understood that the composition can be varied and changed within the limits of physical properties vhereinbefore.

mentioned, and within the limits of the claims.

The alloys coming within the type disclosed in the aforesaid patent must be composed in such a way as to have the required plasticity of the rivet even in their fully heat treated state. They are peculiar in that they only acquire a strength fully comparable to that of duralumin if they are cold worked or stress hardened after quenching and/or after aging. Without such work hardening they are too soft. It is evident that the heads of a rivet get this required work hardening but the shank of the rivet is not work hardened to the'sameextent as the heads and, therefore,

not so strong. The shank is subjected to shearing stress and it has heretofore been understood that strength in shear always is in a certain relation to tensile strength. However, we have found that such is not the case with these alloys .when the work hardening is produced by rolling or drawing but it is the casewhen the work hardening consists in compression or upsetting. It is, therefore, evident that to give the shank the required strength it must be upset. Thisupsetting oitheshankistoacertain extent accomplished in a riv t producing machine because the hole in the die must always be somewhat larger than the wire from which the rivetismade. Iithewireisottoosmalldiameter the head comes eccentric on the shank. In ordinary practice such-upsetting amounts only to from one to three per cent difference in diameter between the original wire and'the finished rivet. Another upsetting is madein the iinal closing up of the rivet'because the hole is generally made somewhat larger in diameter than- -theshankottherivet. 'I'hetotalupsettingoi the rivet is, therefore, in maximum. as 6% increaseindiameter. l 'ormanyilumbmthisum. setting is enough but when it comes to rivets i'or aircraits and automobiles, greater strength 4 is required. As will be hereinafter-described, we

cution: '(ai Selection oi'an aluminum subject to much spontaneous a ing and plastic have fond means 01' increasing the upsetting in the rivet making by departing irom conventional circular wire section. It may be done by upsettingtheshankinaspecialdiesimultancouslywith the making'oi' the rivet orbeiore' or after the head is iormed,butamoreconvenientway isto usepolygon shapedwireand oneop'eration. In this way-we are able to produce rivets which are superiorinshearingstrmgthtoanyaluminum alloy rivets that'we know-of.

The process of fabrication of aluminum alloy rivets which, according to the present invention.

overcomes the hereinbetore enumerated objections,consistsinthetollowingsteps. An alley.

or thetypestatedisselectedwhiohissuitableior the purpose. The alloy is drawnto wire 01' the ornot enoughevenai'tera'workhardenin'gmm "m v i' titeatlnenh(lnllakingwlre oi'suohalloy oi shapeand workhardeningoi'therivetshankinthedieoi to hardeninginroundwire'isonlypossible, extentoiaiewp'ercenhbeeausethewire be held near and centered in the hole of the die. Our preferred wire section is hexagonal with fairly well rounded corners. It is evident that the same results may be obtained by other ways of upsetting the'metalin the shank and we do not wish to limit our invention to the use of polygonshaped wire for such purposes. (c) Quenching or subjecting. the wire to a solution heat treatment. (d) Producing the rivet in arivet making machine provided with means for upsetting of the shank. (e) Aging the rivets with control of agingtemperatureandtimeoiaginginsucha' way that rlvetsot the correct temper are produced.

We claini:

1.'The process of manuiacturing rivets from aluminum alloys susceptible to heat treatment comprising forming a wire of non-circular crosssection, upsetting said wire to iorm rivets having shanks oi cross-section greater than the wire,

saidshanh bcingnpsetwithinacircular'die to -impartacircularcross-sectiontotheshanks.

' 2. The proces ot'manuiacturing rivets from aluminum alloys which comprises forming a-head onawireoipolygonalcross-sectionandupsetting thewlretoformashankofcircular H w: a.

3. The proc'us 01' manufacturing rivets from artiflcially'aging aluminum alloys characterised by their low silicon content and non-spontaneoil 'aging making the rivets from quenchedwireJheshanksoIsuchrlvetshavinga eras-section gr'eaterthanthatot'thewire,said greater cross-sectionbeingproduced byupsetting whilecoldandprodiicfngsuchatemperhyaging atap ior apredeterminedtimetotheanalysisottheailoy,

that the rivets may beheaded up without becom- .ingtoo brittle.

-'4.Theprocessofmanutacturingrivetsirom by their low silicon content and non-spontane- -.ous aging eomprising'mnking the-rivets troni.

.quenchedwire,workhardeningtheshanksthereoi'by upsettingcoldandproducingsuchatemper byagingata temperature fora predeterminedtimeaceordingtoflie analysis 01 thealloyfihattherivetsmaybeheadedupwithout beeomingtoohrlttle.

5. The process or manuiacturing' rivets .i'rom' artificially aging aluminum alloys characterised by their low silicon content and non-spontaneousagingcomprising'themakingoirivetblanks from quenched wire, upsetting the same while cold,ma kin"g'rivets rromsuchupsetblanks and producingsmhatcmperbyagingatapredeteri minedtcmperatureiora cording totheanalysisoftheallomthattherlvetsina'ybeheadedupwithouttoobrittle.

6. The process of'manuiacturing rivets Ironiartificially aging aluminum alloys characterised by their low silicon content and non-spontaneous aging the making of wire ot'a makingrivetsiromsuchquenchedwire,'luchrivetshavingshanksotsubstantialiygreatercross sectionalarea'thansaidwire.said greatercrossbeing produced by upsetting while-cold,

part a cross-section to theshanks, and w clng i mbllml apredetcrmined temperature torapredetermincdtime acemu-section, quenching the same.

saidupsettingbeingwifliinacirculardietoim-fl cording totheannlysisof the alloyrthatthe rivets maybeheadedupwithouttoobrlttle.

mnemormsnuia tunngnveismm artiiiciallyaglngaluminumalloyscharacterised'll aocaovr by their low silicon content and non-spontaneous aging comprising over 92% aluminum, .5% to 1% of nickel, .1% to 1% of copper, 125% to .5% chrome group metals and/or manganese and about .5% magnesium, which comprises the making of rivets from quenched wire, the shanks-of such rivets having a cross-section greater than that of the wire, said greater cross-section being produced by upsetting while cold, and producing is formed. 7

11. The process of manufacturing rivets from artificially aging aluminum alloys characterized by their low silicon content and non-spontaneous aging comprising the making of rivets from quenched wire, upsetting the shanks thereof while cold, providing them with a cross-section greater 5 than the wire, aging the rivets at a temperature of the order of about 300 F. and adjusting the temperature and the time of aging according to the analysis of alloy so as to produce such a such a temper byaging at a predetermined temtemper that the rivets may be headed up without 10 per-ature for a predetermined time according to becoming too brittle. the analysis of the alloy, that the rivets may be 12. The process .of manufacturing rivets from headed up without becoming too brittle. artificially aging aluminum alloys characterized 8. The process of manufacturing rivets from by their low siliconcontent and non-spontaneous l5 artificially aging aluminum alloys characterized aging comprising over 92% aluminum, .5% to 1% by their low silicon content and 'non-spontane-v of nickel, .1% to 1% of copper, 25% to .5% of v ous aging comprising over 92% of aluminum, 5% chrome group metals and/or manganese and v to 1% of nickel, .1% to 1% of copper, 25% to .5% about .5% magnesium, which comprises making chrome group metals and/or manganese and rivets of quenched wire, upsetting the shanks about .5% magnesium, which comprises the makwhile cold to provide them with a greater cross- 20 ing of rivets from quenched wire, work hardensection than the wire, aging the rivets at a teming the shanks thereof by upsetting cold and properature of the order of about 300 F., and adjustducing such a temper by aging at a predetermined ing the temperature and the time of aging actemperature for a predetermined time according cording to the analysis of the alloy so as to proto the analysis of the alloy, that the rivets may be duce such a temper that the rivets may be headed. 25

headed up without becoming too brittle. up without becoming too brittle.

9..Ihe process of manufacturing rivets from 13. The process of manufacturing rivets from artificially aging aluminum alloys characterized artificially aging aluminum alloys characterized by their low silicon content and non-spontaneous by their low silicon content and non-spontaneous aging comprising over 92% of aluminum, .5% to aging comprising making rivets of quenched wire 30 1% of nickel, .1-% to 1% of copper, 25% to v.5% of polygonal cross-section, upsetting the shanks chrome group metals and/or manganese and while cold 'to provide .them' with a greater cross about .5% magnesium, which comprises the maksection than the wire, aging the rivets at a teming of rivet blanks from quenched wire, upsetting perature of the order of about 300,F., and adjust-- the same while cold, making rivets from such ing the temperatureand time of aging and ac- 35 blanks and producing such a temper by aging at cording to the analysis of the alloy so as to pro- .a predetermined temperature for apredetermined .duce vsuch a temperature that the rivets may be time according to the analysis of the alloy, that headed up without becoming too brittle. Y the rivets may be headed up without becoming too 14. The process of manufacturing rivets from brittle. aluminum alloys of 'theclass described character- 40 10. The process of manufacturing rivets from ized by the fact that the alloy has sufficient artificially aging aluminum alloys characterized plasticity for'riveting purposes after quenching by their low silicon content and nun-spontaneous and aging yet is deficient in shearing strength ing ompri in over 92% of aluminum. .5% to without work hardening by compression or up-. 1% of nickel, .1% to 1% of copper, 25% to .5% setting which comprises increasing the cross- 45 chrome cr p m t and/or manganese and sectional area 'ofthe shank defining P i of about .5% magnesium, comprising forming a wire the rivet by at least 5% by an upsetting operaand upsetting said wire to form a. rivet having a tion within adie whereby the shearing strength 1 shank which has at least a 5% greaterarea of of the rivet is comparable with the upset heads of cross-section than said wire from whichthe rivet the rivet in use. .5

even a. warm a. mom.

CERTIFICATE or connection.

i atent No 2,062,977. December 1, 1936'.

SVEN n. HYBINET'I'IE, ET AL.

It is hereby certified that error appears] in the 'printed specification of the above numbered patent requiring correction asfollows: vPage 3, first "column, line 1'7, claim-8, "for "5%" read .5%; and that'the said Letters Pat-f .ent should be read with this correction therein' that the same may conform to-the record'of the case in the Patent Office. Signed and 'eealed this 2nd. day of February, A. D. 1937 Leslie Frazer I n I Aot ing co nmiseioner of Patents.

(Seal) aocaovv by their low silicon content and non-spontaneous aging comprising over 92% aluminum, .5% to 1% of nickel, .1% to 1% of copper, 125% to .5% chrome group metals and/or manganese and about .5% magnesium, which comprises the making of rivets from quenched wire, the shanks-of such rivets having a cross-section greater than that of the wire, said greater cross-section being produced by upsetting while cold, and producing 11. The process of manufacturing rivets from artificially aging aluminum alloys characterized by their low silicon content and non-spontaneous aging comprising the making of rivets from quenched wire, upsetting the shanks thereof while cold, providing them with a cross-section greater 5 than the wire, aging the rivets at a temperature of the order of about 300 F. and adjusting the temperature and the time of aging according to the analysis of alloy so as to produce such a such a temper byaging at a predetermined temtemper that the rivets may be headed up without 10 per-ature for a predetermined time according to becoming too brittle. the analysis of the alloy, that the rivets may be 12. The process .of manufacturing rivets from headed up without becoming too brittle. artificially aging aluminum alloys characterized 8. The process of manufacturing rivets from by their low siliconcontent and non-spontaneous l5 artificially aging aluminum alloys characterized aging comprising over 92% aluminum, .5% to 1% by their low silicon content and 'non-spontane-v of nickel, .1% to 1% of copper, 25% to .5% of v ous aging comprising over 92% of aluminum, 5% chrome group metals and/or manganese and v to 1% of nickel, .1% to 1% of copper, 25% to .5% about .5% magnesium, which comprises making chrome group metals and/or manganese and rivets of quenched wire, upsetting the shanks about .5% magnesium, which comprises the makwhile cold to provide them with a greater cross- 20 ing of rivets from quenched wire, work hardensection than the wire, aging the rivets at a teming the shanks thereof by upsetting cold and properature of the order of about 300 F., and adjustducing such a temper by aging at a predetermined ing the temperature and the time of aging actemperature for a predetermined time according cording to the analysis of the alloy so as to proto the analysis of the alloy, that the rivets may be duce such a temper that the rivets may be headed. 25

headed up without becoming too brittle. up without becoming too brittle.

9..Ihe process of manufacturing rivets from 13. The process of manufacturing rivets from artificially aging aluminum alloys characterized artificially aging aluminum alloys characterized by their low silicon content and non-spontaneous by their low silicon content and non-spontaneous aging comprising over 92% of aluminum, .5% to aging comprising making rivets of quenched wire 30 1% of nickel, .1-% to 1% of copper, 25% to .5% of polygonal cross-section, upsetting the shanks chrome group metals and/or manganese and while cold 'to provide .them' with a greater cross about .5% magnesium, which comprises the maksection than the wire, aging the rivets at a teming of rivet blanks from quenched wire, upsetting perature of the order of about 300,F., and adjust-- the same while cold, making rivets from such ing the temperatureand time of aging and ac- 35 blanks and producing such a temper by aging at cording to the analysis of the alloy so as to pro- .a predetermined temperature for apredetermined .duce such a temperature that the rivets may be time according to the analysis of the alloy, that headed up without becoming too brittle. Y the rivets may be headed up without becoming too 14. The process of manufacturing rivets from brittle. aluminum alloys of 'theclass described character- 40 10. The process of manufacturing rivets from ized by .the fact that the alloy has sufficient artificially aging aluminum alloys characterized plasticity for'riveting purposes after quenching by their low silicon content and nun-spontaneous and aging yet is deficient in shearing strength ing p i ing over 92% of aluminum. .5% to without work hardening by compression or up- 1% of nickel, .1% to 1% of copper, 25% to .5% setting which comprises increasing the cross- 45 chrome cr p m -e and/or manganese and sectional area 'ofthe shank defining P i of about .5% magnesium, comprising forming a wire the rivet by at least 5% by an upsetting operaand upsetting said wire to form a. rivet having at tion within adie whereby the shearing strength 1 shank which has at least a 5% greaterarea of of the rivet is comparable with the upset heads of cross-section than said wire from whichthe rivet the rivet in use. 1

isformed. SVEN E. HYBINE'II' E. TINGAY.

CERTIFICATE or connection.

l atent No 2,062,977. December 1, 1936'.

SVEN n. HYBINET'I'IE, ET t.

It is hereby certified that error appears] in the 'printed specification of the above numbered patent requiring correction as follows: Page 3, first "column, line 1'7, claim-8, "for "5%" read .5%; and that the said Letters Pat-f ent should be read with this correction therein' that the same may conform to-the record'of the case in the Patent Office. Signed and 'eealed this Zndday of February, A. D. 1937 h Leslie Frazer I n I h Aoting co nmiseioner of Patents.

(Seal) 

